The concept of the game reminds me of Trine or the classic The Lost Vikings, both of which I really enjoy same as your game. The ant theme and the necessity of cooperation are great elements here. In both games I mentioned, all characters need to reach the end, not just one, which reinforces the idea of helping each other. This could be a valuable addition to your game as well.
I also like the constructor character; within the ant theme, it brings to mind the image of ants forming living bridges. Perhaps your game could incorporate a mechanic similar to the old Lemmings game, where the goal is to build a path and minimize losses. You could have a bigger number of ants and the player could give them orders to build bridges, dig tunnels, or fly around. Just the idea about possible development of ant theme and your great game ;)